BRCA1 and breast cancer: Overall 20-year survival in the cohort for all women for breast cancer specific survival was 98.8% (95% CI 98.3–99.1%) and for known BRCA1 carriers (n = 365) = 96.1% (95% CI 90.5–98.4%) and BRCA2 (n = 376) = 91.5% (95% CI 78.6–96.8%).